3 ms·

This is what I came across: > Helion has demonstrated the concept[4] in a D–D reactor with plasmoids that fire once every three minutes, and it is now seeking

This is what I came across: > Helion has demonstrated the concept[4] in a D–D reactor with plasmoids that fire once every three minutes, and it is now seeking $15 million in private financing over the next five years to develop a full- scale machine that could use D–T fuel to reach the break-even point, when it generates as much energy as it takes to run. The company hopes that its reactor could eventually reach the hotter conditions needed to fuse deuterium with helium-3, another combination that produces only α-particles and protons, with no neutron by-products. https://www.researchgate.net/profile/Mitch-Waldrop-2/publication/264204212_Plasma_physics_The_fusion_upstarts/links/53e0dfa20cf24f90ff60be1f/Plasma-physics-The-fusion-upstarts.pdf https://www.researchgate.net/profile/Mitch-Waldrop-2/publica... - [4] https://iopscience.iop.org/article/10.1088/0029-5515/51/5/053008 https://iopscience.iop.org/article/10.1088/0029-5515/51/5/05... (https://sci-hub.se/https://iopscience.iop.org/article/10.1088/0029-5515/51/5/053008 https://sci-hub.se/https://iopscience.iop.org/article/10.108...)

sbierwagen 4y ago
>produces only α-particles and protons, with no neutron by-products. Magnificent use of weasel wording there. D-He3 is aneutronic, but of course a mixed plasma hot enough for that reaction is going to have tons of fusions among deuterons, producing plenty of neutrons. I'm not sure if the sky high price of helium-3 is worth just reducing the neutron output of a reactor, rather than eliminating it.
- DennisP 4y ago
  It's intentionally a hybrid of D-D and D-He3. The output of D-D is half He3, and half tritium which decays to He3 with a 12-year half-life. So the only external input is actually deuterium. I've seen Helion and other say that the combined reaction will release 6% of its energy as neutron radiation. That's low enough to skip a heat cycle, which is the real benefit since it substantially lowers your capital cost. That's why Helion estimates a cost starting at $0.01/kWh, and less as they get into mass production.

sbierwagen 4y ago

>produces only α-particles and protons, with no neutron by-products. Magnificent use of weasel wording there. D-He3 is aneutronic, but of course a mixed plasma hot enough for that reaction is going to have tons of fusions among deuterons, producing plenty of neutrons. I'm not sure if the sky high price of helium-3 is worth just reducing the neutron output of a reactor, rather than eliminating it.

DennisP 4y ago
It's intentionally a hybrid of D-D and D-He3. The output of D-D is half He3, and half tritium which decays to He3 with a 12-year half-life. So the only external input is actually deuterium. I've seen Helion and other say that the combined reaction will release 6% of its energy as neutron radiation. That's low enough to skip a heat cycle, which is the real benefit since it substantially lowers your capital cost. That's why Helion estimates a cost starting at $0.01/kWh, and less as they get into mass production.